machined: remove redundant sd_notify

We already call this on via bus_event_loop_with_idle on exit. This
makes machined consistent with other similar daemons: localed,
hostnamed, timedated.

src/machine/machined.c

@@ -349,10 +349,6 @@ int main(int argc, char *argv[]) {
         log_debug("systemd-machined stopped as pid "PID_FMT, getpid());
 
 finish:
-        sd_notify(false,
-                  "STOPPING=1\n"
-                  "STATUS=Shutting down...");
-
         if (m)
                 manager_free(m);